Surveillance of measles antibody levels in local and migrant populations of Jinhua city

Objective This study outlines the measles immunity among local and migrant people in Jinhua city, providing the basis for development of measles elimination strategies. Methods Using 7 age groups (＜ 1 year,1 to 2 years,3 to 4 years,5 to 6 years,7 to 14 years,15 to 19 years, and 20 years),840 subjects were selected from rural townships or residents communities, consisting of 630 local residents,90 from each age group; and 210 immigrants,30 from each age group. The participants were subject to serological quantification of measles IgG antibodies by ELISA, and surveyed for measles history, related immune history and other basic information. Results The positive rate, effective protection rate and Geometric Mean Concentration (GMC) of measles antibody in local population were 92.54％,78.73％ and 1774.19 mIU/ml, respectively. For migrant population, the values were 66.67％,40.95％ and 269.90 mIU/ml, respectively. The positive rate, protection rate and GMC of local population were significantly higher than those of immigrants (P=0.000). The vaccination rate among the local was 82.38% (519/630), remarkably higher than that in the immigrants (12.86%) (27/210, 2=333.75,P=0.000). Conclusion The measles immunity is higher in local residents of Jinhua city than in immigrants who have a generally low vaccination rate. Thus comprehensive measures should be implemented to improve immigrants overall measles antibody levels, such as strengthening inoculation management for migrant children, carrying out emergency vaccination, and providing immunization for new students and employees from other places.